Jens,
The workaround you suggested has a problem if the PlotMarker Circle[]
is altered to a different radius.
ListPlot[{{{1, 1}}, {{1, 2}}},
PlotMarkers -> {HoldForm at Graphics[{Hue[0.5], Circle[{1, 1}, 0.01]}],
HoldForm at Graphics[{Hue[0.96], Circle[{1, 2}, 2]}]}]
Does not change the PlotMarker circle radius at all in either case.
This seems like a bug and I have reported it to WRI.
Syd Geraghty B.Sc, M.Sc.
sydgeraghty at mac.com
Mathematica 7.0.0 for Mac OS X x86 (64 - bit) (21st November, 2008)
MacOS X V 10.5.6
MacBook Pro 2.33 GHz Intel Core 2 Duo 2GB RAM
On Jan 12, 2009, at 3:24 AM, JUN wrote:
> in Mathematica 7 on Mac OS X, try to execute this simple example:
>
> ListPlot[{{{1, 1}}, {{1, 2}}}, PlotMarkers -> {Graphics[{Hue[0.5],
> Circle[]}], Graphics[{Hue[0.96],Circle[]}]}]
>
> Whereas this works in Mathematica 6.03, there is now the error
> "An improperly formatted option was encountered while reading a
> GraphicsBox. The option was not in the form of a rule."
>
> This is apparently caused by any graphics directive (such as Hue,
> Opacity, Thickness), but I was able to reliably work around it by
> replacing Graphics with HoldForm@Graphics.
>
> There seems to be no problem with Graphics3D markers, and according to
> the documentation there should be no problem with arbitrary Graphics
> as plot markers, either. I'm guessing there has been some subtle
> change in Graphics' inner workings that conflicts with its use in
> PlotMarkers - but who knows.
>
> Anyway, HoldForm is the cure, in case anyone else stumbles over this
> issue.